Radioactive labeling of proteins is a very important technique used in neurological research to identify, isolate, and investigate the expression and properties of proteins in biological systems. In such procedures, the preferred radiolabel is often tritium and other low energy beta emitters such as 14C and 35S. Presently, binding assays involving tritium are carried out using inconvenient and expensive techniques which rely on the use of scintillation cocktails. This traditional method involves both time- consuming laboratory protocols and the generation of substantial quantities of radioactive and chemical waste. In the Phase I project, a monolithic, multi-element, solid-state array of sensors was developed to directly measure the tritium content of biological specimens. Using this technique, the tritiated samples can be positioned directly under an array of unique solid-state tritium sensors which rapidly sense and record the amount of radioactivity present at each point within the array field of view. A surface treatment was established to essentially double the intrinsic tritium beta detection (to 50%). Biological sample testing was carried out which demonstrated that it will be possible during the Phase II project to develop an instrument with much higher sample throughput compared to standard evaluation methods. Such a system, by eliminating much of the work of sample preparation and by increasing the speed of measurement, can provide superior sample throughput for a wide variety of tritium binding studies as well as other commonly used radiolabled tags. PROPOSED COMMERCIAL APPLICATION: Many biomedical facilities now use expensive counting systems which run continuously to keep up with constant flow of samples to be measured. A flexible, digital-based instrument which can directly detect tritium and all other common radiolabels would provide improved cost effectiveness and greatly reduce the problems associated with hazardous waste. This would find a good commercial market.